Research on New Ultrasonic Implementation for Aviation. Phase 1. Final Report

摘要

The study applied ultrasonic techniques to aircraft instruments, seeking innovative devices for general aviation. Detection of icing, and rate of turn, were emphasized. Icing, and ice removal, were found to have received intensive investigation, using vibration and ultrasound, in programs supported by NASA. Problems yet remain, involving transducer and vibration signature innovations. Vibrating rate of turn instruments, such as the Sperry Gyrotron and the GE VYRO, while difficult to manufacture, are small and especially reliable, since no gyroscope bearings are used. Researchers investigated a single bar instrument, based on the GE metal and ceramic device. Stability problems in metal were alleviated by using a fused quartz bar. Cost problems related to the piezoelectric ceramic transducers were attacked by using a single thin film sheet of PVDF polymer, with electrode arrays formed by photoetching, and attached to the quartz in one operation. Equivalent circuit analysis provided an accurate model, predicting the mechanical quality factor and frequency response of the resonant structure.